1. Field of the Invention
The present invention relates to a multipoint object distance measurement auto focus camera having a plurality of object distance measuring zones.
2. Description of Related Art
An auto focus camera having a plurality of object distance measuring zones has been developed to prevent measuring light from passing between objects (e.g. two human figures) to be taken, so that an object distance can not be measured. Namely, if an object distance measuring zone is located only at the center of the picture plane, it is impossible to set a focal point on an object which is not in the center portion of the picture plane. To avoid this, a plurality of object distance measuring zones are provided, for example, on the center of the picture plane and the circumferential portions thereof, so that a focus is determined, based on an object which is located in one of the object distance measuring zones. The selection of the object distance measuring zones can be done in accordance with an algorithm of an associated camera or by a photographer's choice.
However, in a known multipoint object distance measurement auto focus camera, whichever object distance measuring zone is selected, a focus can be obtained only in one plane which is located at a specific distance from a film, provided that the depth of field is ignored. Namely, it is impossible to set a focal point on objects of different distances. In other words, in a conventional auto focus camera of the kind mentioned above, there is no concept in which a focal point is determined based on as many as possible object distance measuring zones.